FOR ETF INVESTORS - ALLOCATIONS ON HISTORY
ETF backtesting for allocation ideas
Describe a rotation or an allocation in plain English and AgentTrading tests it on 20+ years of adjusted history, dividends reinvested, with the regime dependence named in words.
ETF investors testing rotations, trend filters, and allocation mixes who want honest history instead of a flattering chart.
- 1 THESIS
- 2 EVIDENCE
- 3 BACKTEST
- 4 RISK
- 5 VERDICT
02 EVIDENCE · FUNDAMENTALS
04 RISK · IN PLAIN ENGLISH
Sample scenarios, not a live backtest of what you typed. Past performance does not guarantee future results. Educational analysis only, not financial advice.
In short
ETF backtesting turns an allocation hunch into a tested rule: describe the idea in plain English, such as "shift between SPY and bonds on the 200-day trend" or "rebalance a three-fund mix quarterly", and AgentTrading restates the rule, runs it on 20+ years of split- and dividend-adjusted daily data with dividends reinvested and a 0.1% cost per trade assumed by default, then stamps an honest verdict against buy-and-hold. Rotation ideas are exactly where honesty earns its keep: rules that look brilliant in one regime often grade MIXED across the full record, and the risk panel names the regime dependence in plain English instead of letting one good decade flatter the rule. The usual tool here is Portfolio Visualizer ($0 to $55 per month), which will compute the statistics through a long configuration form and leave the interpretation to you; AgentTrading starts at $19 per month, and takes a sentence as input and writes the interpretation. Costs are counted on every rebalance, because an allocation rule that only works with zero costs fails in the real world first. One honest limitation: coverage is US-listed ETFs and stocks on daily bars. No execution, no advice, no recommended portfolio: educational analysis of your allocation idea, and the allocation itself remains your decision.
Past performance does not guarantee future results. For educational and informational purposes only. Not financial advice. Consult a licensed advisor.
ON YOUR BENCH - ETF INVESTORS
What changes when the vetting is honest
Rotations tested across regimes
A rotation that shines in one market and sags in another gets that sentence attached to its verdict. The risk panel names regime dependence in words instead of letting one good decade flatter the rule.
Dividends reinvested, costs counted
Every test runs on 20+ years of split- and dividend-adjusted data with dividends reinvested and 0.1% assumed per trade, so frequent rebalancing pays its real toll inside the backtest, not after it.
Trade-offs stated, not sold
Lower drawdown usually costs growth, and the verdict prints both halves. An allocation idea that HELD UP on one measure and trailed on another is described exactly that way, every time.
A sentence is the whole setup
"Shift between SPY and bonds on the 200-day trend" is a complete specification here. No configuration form, no ticket of dropdown menus, and the restated rule card is your check before the run.
THE MATH - TIME, NOT MAGIC
The manual loop is 4 to 6 hours per idea
A screener, ten filings, and a spreadsheet backtest, for every single idea. The bench runs the same loop in minutes and logs what it assumed. Count what that is worth in your week.
Your research hours, backTIME ONLY. NO RETURN MATH.
Manual vetting / month
h
Hours back with the bench
~h
On the same bench
Allocation rules are built in the trading strategy builder, a sentence at a time, and run on the adjusted record described on historical stock data. The full bench walkthrough is on backtesting software, and single-name research gets the persona view on stock research tools for long-term investors.
QUESTIONS - ASKED AND ANSWERED
ETF investors: the common questions
Can you backtest an ETF portfolio?
Yes. Describe the allocation and the rule that changes it, for example hold an equal weight sleeve rebalanced quarterly, and it runs on 20+ years of split and dividend adjusted daily data with 0.1% charged per trade by default and distributions reinvested, benchmarked against holding the same sleeve untouched over identical dates.
How far back can you backtest an ETF?
Only as far as the fund has existed, which is the constraint people hit first. Many popular ETFs launched after 2000 and a good number after 2010, so a twenty-year test simply is not available for them. Where history is short, say so in your conclusion rather than quietly testing a shorter window and presenting it as the same evidence.
Does rebalancing actually improve returns?
Not reliably in return terms, and that surprises people. Rebalancing is primarily a risk control: it keeps the portfolio near its intended allocation and trims whatever has run. In backtests it often costs a little return in strongly trending markets and reduces drawdown and dispersion. Test the frequency you plan to use, because quarterly and annual behave differently.
What is the difference between ETF backtesting and portfolio backtesting?
The distinction is what changes. Portfolio backtesting usually tests a fixed allocation and a rebalancing schedule. ETF backtesting as used here also covers rules that move between sleeves, such as rotating on relative strength or moving defensive on a moving average signal. The second kind produces entries and exits, so trading costs matter far more.
Do expense ratios matter in a backtest?
They matter more than most people assume over long horizons, because they compound every year regardless of what the market did. A 0.60% fund against a 0.05% fund gives up roughly 11 percentage points of cumulative return over twenty years before any difference in performance. Costs charged per trade are separate and stack on top.
Past performance does not guarantee future results. For educational and informational purposes only. Not financial advice. Consult a licensed advisor.
Who else runs the bench
Your next idea deserves a verdict, not a hunch.
Bring a thesis or a ticker. Get the evidence, the backtest, the risks, and an honest stamp. Then decide for yourself.
Past performance does not guarantee future results. For educational and informational purposes only. Not financial advice. Consult a licensed advisor.